assume cs:codesg, ds:datasg, ss:stacksg
stacksg segment
            dw 0, 0, 0, 0, 0, 0, 0, 0
stacksg ends
datasg segment
           db '1. display      '
           db '2. brows        '
           db '3. replace      '
           db '4. modify       '
datasg ends
codesg segment
    start: mov  ax, stacksg
           mov  ss, ax
           mov  sp, 10H

           mov  ax, datasg
           mov  ds,ax

           mov  cx, 4
           mov  bx, 0             ; line
    s:     push cx
            
           mov  si, 3             ; col
           mov  cx, 4
    s0:    mov  al, ds:[bx+si]
           and  al, 11011111B
           mov  ds:[bx+si], al
           inc  si
           loop s0
            
           add  bx, 10H
           pop  cx
           loop s

           mov  ax, 4c00h
           int  21H

codesg ends
end start